1. Field of the Invention
The present invention relates to air pumps and, more particularly, to an electromagnetically-driven reciprocating air pump.
2. Description of the Related Art
An electromagnetically-driven reciprocating air pump usually has a piston assembly of a pair of pistons and an armature connecting the pair of pistons in the state that the pair of pistons are axially aligned with each other. The air pump further has electromagnets installed at the opposite sides, respectively of the armature. When an alternating electric current is applied thereto, the electromagnets generate an alternating magnetic field to reciprocate the armature in the axial direction of the pistons. Further, the air pump has a pump casing having a pair of cylinder chambers slidably accommodating the pair of pistons, respectively, and a drive chamber accommodating the armature extending between the cylinder chambers and accommodating the electromagnets.
In the above-described pump casing, electromagnet pedestals are formed to project from the inner wall surface of the casing into the drive chamber to set the electromagnets at respective proper positions with respect to permanent magnets attached to the armature transversely extending in the drive chamber. The electromagnets are secured to the electromagnet pedestals. Accordingly, the electromagnet pedestals will interfere with the installation of the pair of pistons if the pistons are connected together into a piston assembly by the armature, as stated above, and the piston assembly is inserted into the casing through one cylinder chamber of the casing so as to extend as far as the other cylinder chamber. Therefore, with conventional air pumps of this type, the pistons are inserted into the cylinder chambers from the left and right sides of the casing, respectively, and after having been installed in the cylinder chamber, the pistons are connected to each other by the armature.
However, such a piston installation operation is complicated and time-consuming. Therefore, there has been a demand for the pistons to be capable of being installed more easily.
The present invention provides an air pump capable of meeting the above-described demand.